Lightly Surfaced Roads. Chuck Jahren and Francis Dayamba. Photo taken by Francis O Dayamba

Transcription

1 Lightly Surfaced Roads. Chuck Jahren and Francis Dayamba Photo taken by Francis O Dayamba

2 Motivation fatigue-cracking-alligator-cracking

3 Presentation Outline Define Light Surface Treatment Important Factors for success in applying Light Surface Treatments Outline of treatments discussed in presentation LRRB County Engineer Survey How to strengthen Subgrade/Subbase? LST applied in other regions of the world Alternative to Light Surface Treatment Future Activities Questions and Comments

4 Define Light Surface Treatment Definition: A thin surface treatment of liquid asphalt covered with an aggregate that has an applied thickness of about 0.5-inch or less. -WSDOT

5 Important Factors for success Quality of Subgrade and Subbase Experience of contractor Quality of centerline joint and intersections Appropriateness of geometry and pavement markings

6 Outline of treatments discussed in presentation Strengthening of Base Fly Ash Calcium Chloride and Magnesium Chloride Macadam Stone/Iron- Mining Products Geogrids and Geotextile Proprietary Products Base One Geocells Light Surface Treatments and Alternatives Chip Seal Otta Seal Slurry Seal Cape Seal RAS and RAP

7 LRRB County Engineer Survey 36 total Respondents Number of Counties Survey Results 8 Otta Seals 2 Chip Seals 23 None Applied 2 Magnesium Chloride 1 Permazyme

8 LRRB County Engineer Survey Otta Seal Picture taken by Francis Dayamba Stillwater, MN Picture taken by Chuck Jahren Charles Overby and Francis Dayamba TRB, Washington D.C Otta Seal Guide Norway- NPRA

9 LRRB County Engineer Survey Chip Seal Pavement Interactive Website Bituminous surface Treatment

10 How to strengthen Subgrade/Subbase? Fly Ash Base One Macadam Stone Many Proprietary Products

11 How to strengthen Subgrade/Subbase? CaCl2 and MgCl2 Geogrids and Geotextiles stewardship/accessroads/ geotextiles.htm Miragrid/PDS_Miragrid0207.pdf

12 How to strengthen Subgrade/Subbase?-Geocells 100% recycled plastic Benefits Dust reduction Maintains gravel Can handle heavy equipment Permeable Cost Reduced installation time

13 LST applied in other regions of the world Cape Seal Chip Seal followed by a slurry/micro-surfacing Alleviates cracking and provides smooth/hardwearing surface %20Maintenance/Pages/CapeSeal.aspx

14 LST applied in other regions of the world Sand Seal Emulsion followed by two layers(1/4-1/2 ) of sand/fine(3/8 ) aggregate Uses On top of Subgrade On top of Chip Seal/Otta Seal Useful for areas with low supply of stone aggregate and high sand/fine aggregate Limited ADT

15 LST applied in other regions of the world Macadam/Iron Mining By-Products Compacted layer(s) of large stone (Max 4 ) Seal Coat on surface Hauling more than 20 miles(uneconomical in Iowa)

16 Alternative to LST-RAS and RAP FDR, In-place Recycling, Cold-Mix Asphalt and Hot- Mix Asphalt Sustainability Cost effective Reduces dust and surface distresses* *Study by University of Wyoming Department of Civil and Environmental Engineering

17 Future Activities Life Cycle Cost Analysis GIS Project Pavement Design GIS County Map of Minnesota-MnDoT

18 Conclusions Many Alternative Light Surface options exist Big Toolbox, choose the right tool for your application, consider: Available materials and pricing Local Environment conditions Structural Support Must be applied properly Requires more investment in comparison to gravel But can result in: Better road user and stakeholder satisfaction Reduced ongoing maintenance costs compared to gravel

19 Questions? THANK YOU!